Glutathione facilitates enterovirus assembly by binding at a druggable pocket

Helen M E Duyvesteyn,David I Stuart,Elizabeth E Fry,Thomas S Walter,Jingshan Ren

doi:10.1038/s42003-019-0722-x

Helen M E Duyvesteyn, David I Stuart + Show 3 more

Open Access

https://doi.org/10.1038/s42003-019-0722-x

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Abstract

Enteroviruses cause a range of human and animal diseases, some life-threatening, but there remain no licenced anti-enterovirus drugs. However, a benzene-sulfonamide derivative and related compounds have been shown recently to block infection of a range of enteroviruses by binding the capsid at a positively-charged surface depression conserved across many enteroviruses. It has also been established that glutathione is essential for the assembly of many enteroviruses, interacting with the capsid proteins to facilitate the formation of the pentameric assembly intermediate, although the mechanism is unknown. Here we show, by high resolution structure analyses of enterovirus F3, that reduced glutathione binds to the same interprotomer pocket as the benzene-sulfonamide derivative. Bound glutathione makes strong interactions with adjacent protomers, thereby explaining the underlying biological role of this druggable binding pocket and delineating the pharmacophore for potential antivirals.

Highlights

Enteroviruses cause a range of human and animal diseases, some life-threatening, but there remain no licenced anti-enterovirus drugs
We find that the binding site of both compounds is identical to that for a similar molecule that remains naturally attached to the virus[7], and to the binding site observed for the benzene-sulfonamide derivative in complex with Coxsackievirus B38, identifying the biological role for this binding site
EV-F3 is dependent on and stabilised by GSH. Infection of cells both with and without butathione sulfoximate (BSO) treatment shows that inhibition of glutathione synthesis reduces EV-F3 growth by 3.5 log, demonstrating glutathione dependency (Supplementary Table 1)

Summary

Introduction

Enteroviruses cause a range of human and animal diseases, some life-threatening, but there remain no licenced anti-enterovirus drugs. By high resolution structure analyses of enterovirus F3, that reduced glutathione binds to the same interprotomer pocket as the benzene-sulfonamide derivative. A cavity on the capsid surface at an inter-protomer interface, where we previously reported extra electron density[7], has recently been identified as potentially druggable, with micromolar binding for a benzene-sulfonamide derivative[8]. This compound, and a number of related compounds, are inhibitors of Coxsackie B viruses and a range of other enteroviruses including rhinoviruses, and have been shown to act synergistically with P site binders[8]. We find that the binding site of both compounds is identical to that for a similar molecule that remains naturally attached to the virus[7], and to the binding site observed for the benzene-sulfonamide derivative in complex with Coxsackievirus B38, identifying the biological role for this binding site

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